In the conventional assembly of roof plates, each roof plate was connected directly to the other and, accordingly, in the course of roof plate assembly the manufacturing errors in each roof plate and inaccurate clearances at the joints are accumulated into a considerable amount that often made the very connection of the roof plates difficult if not actually impossible within a predetermined area.
The present invention provides a method of assembling the roof plates by means of interlocking each roof plate on its front and rear end with anchoring pieces for eliminating the aforesaid inaccuracies by absorbing the aforesaid errors between the anchoring piece and each roof plate, and further by excluding the constructional dependency between the preceding roof plate and the following one.